Pros: Fantastic visualizations and interactive explorations, deeply informative text, and easy-to-navigate interface all make pure math come alive.Cons: Long sections of dense academic text with tricky vocabulary and sometimes-serpentine hyperlink trails will undoubtably alienate some users. Bottom Line: For students who get bored by the usual curriculum, this tool will open their eyes to math's deepest problems and most curious corners.

Name: Fact Monster Almanac Brief Description of the Site: This site is so cool that youâ€™ll wish you could stick it in your pocket. It is a cornucopia of information in eight major topics: World, US, People, Word Wise, Science, Math, Sports, and Cool Stuff. Each is further subdivided into subtopics, such as